During the project year it is planned to study the responses of neurons within the brain-stem respiratory complex to servo-controlled lung volume changes and to vagal stimulation using cross-correlation techniques. Of interest are the inspiratory neurons in the region of the vagal input station, the solitary tract, with discharge properties consonant with the time dependent threshold of the Breuer-Hering inflation reflex, and also the neurons in the "pneumotaxic" system (medial parabrachial nucleus).